1. Field of the Invention
The invention relates to a telecommunications overvoltage protection magazine.
It is in this field that numerous junction modules mostly in the form of junction blocks are usually provided in suitable rack-mounting systems in distribution points, at least on the line side of which some means of overvoltage protection are needed as a rule.
2. Prior Art
For this purpose overvoltage protection plug-ins (cf. for example DE 39 21 227 C2) or overvoltage protection magazines (cf. subject matter of DE 30 14 796 C2) are known for front junction block mounting. There is the problem with these plug-in overvoltage protection means that the conductors joined to the individual contacts of the junction module are inaccessible or accessible only with difficulty.
Solutions have been proposed to get round this problem (cf. DE 40 08 386 A1) by plugging-in the overvoltage protection magazines above the junction block in accordance with one mounting position of the latter. This, however, substantially increases the space taken up by the combination of the junction block and overvoltage protection magazine in the vertical direction, thus resulting in these solutions being a disadvantage as regards their space requirement.
This applies likewise to the arrangement as it reads from U.S. Pat. No. 4,781,613 in which the connection boxes and protection boxes are alternatingly rack-mountable.
With the distribution board subassembly as it reads from DE 44 23 339 C1 in which the individual surge arresters are designed for rear plug-in mounting at the operational service side the problem remains that each subassembly needs to be designed relatively complicated and it needs to be assured that it has rear access.
The invention is based on the object of providing a telecommunications overvoltage protection magazine which is a compact solution in combination with a junction block for protecting the conductors from overvoltages, especially at the line side of a distribution point.
This object is achieved by the overvoltage protection magazine as it reads from claim 1.
Proposed in accordance with the invention is an overvoltage protection magazine which in a totally novel approach can be directly mounted in a telecommunications rack-mounting system behind a junction zone for cable conductors in accordance with one mounting position. In other words the junction zone for cable conductors corresponding to the front part of a known junction block has front access. This junction zone is electrically connectable to the overvoltage protection magazine in accordance with the invention and thus forms the base element for the novel combination of overvoltage protection magazine and junction zone.
This combination in accordance with the invention does away with the known configuration of a rack-mounted junction block and an overvoltage protection magazine plugged into the junction block. Instead, in accordance with the invention the overvoltage protection magazine is now rack-mounted on which the junction zone is front mounted so that the combination of the two cited components has a low profile and thus takes up little room in the critical direction, namely in the vertical direction of a distribution point. In the depth direction of the distribution point the room taken up is less critical so that the invention in this respect results in no serious disadvantages.
To facilitate inserting the surge arresters in the magazine in accordance with the invention it is good practice when this is done from below, from above or partly from above and partly from below, for example alternatingly from above and below, it being particularly preferred when the surge arresters are all insertable from below. As compared to being inserted from above this has the advantage that the conductors joined to the junction zone, which are usually routed at the top above the overvoltage protection magazine, do not obstruct replacing individual arresters. In this arrangement, however, it may also be provided for that recesses are provided at the top side of the magazine at each arrester location so that pressure can be exerted on the arrester from above by a suitable tool, for instance by a screwdriver, to facilitate removing the arrester from below. However, the arresters may also be plugged-in from above or alternatingly from above and below to thus achieve substantially the same advantages as aforementioned in combination with mounting from below. More particularly, recesses may be provided at the underside of the magazine in accordance with the invention for top-inserted surge arresters to facilitate removing the protection components in this situation, too. Basically the surge arresters may also be devised for rear insertion, this being particularly suitable when the magazine can be removed or swung out of its mounting position so that it is accessible from the rear.
Preferred further embodiments of the overvoltage protection magazine in accordance with the invention read from the further claims.
For the mounting means especially the latching means, provided on the overvoltage protection magazine in accordance with the invention it is preferred that these are provided behind the junction zone as mountable on the overvoltage protection magazine in accordance with the invention and electrically connectable thereto so as not to obstruct work done on the junction zone by parts of the rack-mounting system in which the magazine in accordance with the invention can be mounted. Furthermore, it is preferred for the mounting means of the magazine that these are not only located in the mounting position behind the junction zone but also in a rear portion of the overvoltage protection magazine itself to thus enable, for example, the overvoltage protection magazine to be released to a certain extent from its usual mounting position whilst still remaining connected to the rack-mounting system and rendering the overvoltage protection components accessible for replacement.
It is currently good practice to design the overvoltage protection magazine mountable for retraction from the rack-mounting system. In this case the inserted arresters are directly accessible whilst making it possible to provide a certain spare cabling capacity for the conductors joined to the junction zone so as not to endanger the connection to the terminal contacts. As an alternative the overvoltage protection magazine may be designed swivel-mounted on the rack-mounting system.
As described above, a so-called junction zone for joining the cables is connectable to the overvoltage protection magazine in accordance with the invention as a base component of the resulting combination. Advantages are also to be had, however, when the junction zone and the overvoltage protection magazine are integrated in a single module. This module represents to a certain extent a module in which all necessary functions are integrated, it being, however, just as possible to make use of this module, in other words with one and the same module, without surge arresters being inserted therein should this protection function not be needed.
The protection achieved for the conductors to be protected is particularly comprehensive by it additionally comprising in accordance with a preferred embodiment in the connection between incoming and outgoing conductors an overcurrent protection, more particularly a polyswitch.
To render the overvoltage protection magazine in accordance with the invention useful in combination with a junction zone, especially on the line side of a distribution point, it is good practice when the junction zone comprises not only the opposing contact rows for joining incoming and outgoing conductors but also isolating and test contacts arranged in between.
For circuiting the overvoltage protection magazine in accordance with the invention in combination with a junction zone it is good practice to route all conductors to one side of the overvoltage protection magazine to thus make it particularly simple, for example, to swivel the overvoltage protection magazine about the side to which the conductors are routed so that greatly simplified access to the surge arresters, for example, in the swivelled-open position is provided.